Improvement in casting car-wheels



B. BURGESS. Casting Gar-Wheels.

No. 208,371. Patented se t.'24,1s7s.

NFETERS; PHOTO-UTHQGRAPHER. W ASHKNGTON. D C.

UNITED-STATES PATENT OFFICE BENJAMIN BURGESS, OF BALTIMORE, MARYLAND,ASSIGNOR OF ONE-HALF HIS RIGHT TO JOHN N. GONXVAY, OF SAME PLACE.

IMPROVEMENT IN CASTING CAR-WHEELS.

Specification forming part of Letters Patent No. 208,371, datedSeptember 24, 1878; application filed November 1, 1877.

To all whom it may concern:

Be it known that I, BENJAMIN Bnnenss, of the city of Baltimore and Stateof Maryland, have invented certain Improvements in Gasting Oar-\Vheels,of which the following is a,

specification; and I do hereby declare that in the same is contained afull, clear, and exact description of my said invention, reference be-.ing had to the accompanying drawing, and to stated, is to preventduring the casting operation the accumulation of slag, dross, or scoriaat that part of the wheel termed the tread, or that portion of the wheeldirectly in contact with and acted upon by the rail.

Gar-wheels of the plate description are usually formed either with astraight or circularlycorrugated plate connecting the hub with the rimof the wheel, or with two or more plates of concavo-convex form arrangedconcentrically or occupying reversed positions with reference to the huband rimthat is to say, with the concave or convex sides adjoining.

The object of the various designs of plates above referred to is to givecertain elasticity to the wheel and prevent rupture of any member of thesame by contraction in cooling. In all the above designs, however, themajor part of the molten metal, in passing from the hub portion of themold toward the rim, has either to traverse a declining channel, or ahorizontal or a circuitous one, terminating at the periphery of thewheel. In this movement of the molten metal the slag or dross whichfioats on the surface thereof is carried directly in contact with theface of the mold forming the tread, and the dross or slag becomespermanently fixed at that point by the chilling of the metal around it.

In consequence of the above-described defects in construction, ordinarycar-wheels are usually found to have spongy or soft areas,

which rapidly develop into flat places, thereby rendering the wheelsuseless.

The present invention consists in freeing the tread and other portionsof the wheel designed to come in contact with the rail from scoria andother recrement by pouring the metal at the hub and conducting the metalto the rim, first through the arm-channels, and

subsequently up a plain concavo-c'onvex platechannel. The scoriaconveyed to the hub portion of the mold with the molten metal, togetherwith oxide formed within the mold, floats on the surface of the metal inthe form of a crust, which from its size cannot enter the arm-channelsbefore referred to. The scoria is thus retained in the hub-recess, whichconstitutes a well or reservoir, from which clean metal flows toward therim until the metal rises to the'plate-channel. Upon the metal reachingthe lowest point of the convex upper surface of the mold, a trap iseffected, and the metal is fed from below the crusted surface thereof tothe inclined channel, and thence to the tread of the wheel. The scoriais thus finally carried to the upper surface of the hub, at which placea spongy formation does not injure the wearing properties of the wheel.

Any light impurities entering the inclined channel after the metal risesover the lower edge of the concave under surface of the mold, and beforethe trap is formed, ultimately reach the upper edge e of the wheel,which does not come in contact with the rail.

Figure 1. in the drawing is a sectional view of the wheel-mold, theflasks and other appliances used being of the ordinary and well-approveddescription. Fig. 2 is a sectional plan of the mold on line :10 y ofFig. 1.

The dotted surface represents the sand. The cope A and drag B unite atthe parting a. The gate 1) connects with the hub c of the mold, 0 beingthe metallic chill used to form the tread part thereof. The plainconcavoconvex plate-channel is shown by d, rising to the highest point eof the tread of the wheel. The arm-channels are represented by a.

Having thus described my invention, what I claim as new, and wish tosecure by Letters Patent of the United States, is-

In testimony whereof I have hereunto subscribed my name this 13th day ofSeptember, in the year of our Lord 1877.

BENJAMIN BURGESS.

Witnesses:

W. W. WHARTON, THos. MURDooH.

